Influence of type 2 diabetes and depression on subclinical inflammation in patients with myocardial infarction

Aims: To study the influence of type 2 diabetes mellitus (DM) and depression on subclinical inflammation in patients with myocardial infarction (MI).

Material and methods: 195 patients with a median (Me) age of 58 years (54, 65), admitted to hospital with ST segment elevation myocardial infarction were enrolled in a case-control study. 99 patients (51%) with Me age of 60 years (54, 64) had DM, 96 (49%) with Me 58 years (54, 62) – did not. The age differences between the groups was not considered statistically significant. Diabetic and non-diabetic patients were subdivided into groups according to the depression degree: with depression and without. The levels of interleukin (IL-6, IL-8, IL-10), tumor necrosis factor (TNF), high-sensitivity C-reactive protein (CRP) were measured by solid-phase enzyme immunoassay on 3rd - 5th days after MI onset.

Results: Diabetic patients found higher subclinical inflammatory activity than non-diabetic: IL-6 9.4 (4.9, 11.4) pg/ml and 4.4 (3.6, 5.1) pg/ml, p = 0.02, IL-8 6.4 (4.9, 10.9) pg/ml and 3.7 (2.7, 7.3) pg/ml, p = 0.04, IL -10 3.5 (1.9, 4.1) pg/ml and 6.5 (4.1, 7.2) pg/ml, p = 0.02, TNF 11.7 (9.8, 16.5) pg/ml and 6.9 (5.8, 11 2) pg/ml, p = 0.03; CRP 19.9 (14.6, 23.2) mg/L and 11.4 (7.6, 14.6) mg/L, p = 0.01.The depression provoked subclinical inflammation in MI patients independently of diabetes. Non-diabetic MI patients without depression reported lower level of subclinical inflammation, than those with depression: IL-6, 3.8 (2.9, 3.8) pg/ml and 1.1 (1.5, 2, 5) pg/ml, p=0.03, IL-8 1.9 (1.7, 4.3) pg/ml and 3.6 (2.1, 5.9) pg/ml, p=0.02, IL-10 5.1 (2.8, 4.5) pg/ml and 2.8 (2.5, 3.3) pg/ml, p=0.04, TNF 3.8 (3, 3, 6.8) pg/ml and 6.2 (5.1, 8.7) pg/ml, p=0.04, CRP 6.9 (4.8, 8.5) mg/l and 9.1 (5.6, 12.2) mg/L, p=0.03. Diabetic MI patients without depression found lower levels of inflammation markers than those with depression: IL-6, 4.9 (2.1, 6.5) pg/ml and 6.9 (3.9; 8.1) pg/ml, p=0.02, IL-8 3.4 (2.7, 6.3) pg/ml and 6.1 (4.4, 9.1) pg/ml, p=0.04, IL-10 2.9 (1.5, 3.5) pg/ml and 1.1 (0.9, 1.3) pg/ml, p=0.03, TNF 6.7 (5.7, 9.3) pg/ml and 9.9 (8.2, 14.5) pg/ml, p=0.01, CRP 12.9 (8.5, 13.9) mg/l and 14.1 (12.3, 18.6) mg/L, p=0.04.

The lowest subclinical inflammatory activity was reported in non-diabetic MI patients without depression, while the highest level - in their combination.

Conclusions: DM and depression in MI patients contributed to pronounced subclinical inflammatory activity, which may be associated with MI severity as well as common pathogenesis of these diseases.